I can't create a Jboss monitor

Hello all

I am testing Application Manager to monitor several service in the company.
I am testing Application Manager 7310 running in a Linux machine, and several Jboss running in linux machines too.

When I try to install the Jboss monitor, I have the following error message:
Unable to connect to Jboss server Old-Jack. Check if http-invoker.sar has been deployed in the jboss server.
Root Cause:
Unable to connect to http://Old-Jack:8080/invoker/JNDIFactory from Applications Manager machine. More Help>> Diagnose the Problem?

The jboss (4.0.2) is install by default and the http-invoker seems to be deployed. What must I do to enable it??

Thanks